crypto/tls: Replace errors.New() with error exported variables

[gopherbot]

by edrocksit:

crypto/tls makes heavy use of errors.New() instead of exported error variables. This
requires anyone checking for specific errors to have to do a basic string compare which
is error prone if the error strings crypto/tls uses ever change.

What does 'go version' print?
go1.3.3 windows/amd64

What steps reproduce the problem?
Do something that makes crypto/tls return an error. In my case with the rest api I'm
using approximately 1 of every 30-50 requests returns "remote error: handshake
failure". The only way to test for this and retry is to do a basic string compare.

[ianlancetaylor]

Comment 1:

Labels changed: added repo-main, release-none.

[gopherbot]

CL https://golang.org/cl/27711 mentions this issue.

[agnivade]

@ianlancetaylor / @rsc - From the CL above, it seems this idea was abandoned. I believe this issue can be closed then.